This invention relates to an apparatus for printing data from a facsimile receiver set, an electronic computer or the like, and particularly to an electrostatic printer for printing a single type of data in a great volume.
More particularly, the invention relates to an electrostatic printer which is capable of providing prints on multiple sheets of plain paper by including means for converting into light signals the electrical data signals from a facsimile receiver set, an electronic computer or the like, and means for applying the light signals to an image formation member to thereby visualize the image thereon and for making the image formation member into an electrostatic printing master having an electrical resistance pattern formed thereon, and by repetitively subjecting the electrostatic printing master to the major steps of charging, development and image transfer.
2. Description of the Prior Art
In recent years, the following have come into use as the apparatus for recording the electrical data signals from a facsimile receiver set, an electronic computer or the like and as the recording medium therefor.
As the recording system, there are mechanical impact line printers of the drum type, multistylus electronic printers, printers utilizing CRT and electrophotography, etc. The mechanical impact line printers have been disadvantageous in that they are limited in speed and very noisy and poor in reliability. The multistylus electrostatic printers have been limited in resolving power and require expensive electrostatic recording paper to be used as the recording medium. The printers utilizing CRT have offered the problem that the sensitivity of the photosensitive medium becomes insufficient when such printers are adapted for high-speed operation.
In any of these recording systems, it has been necessary to provide separate copiers in order that the record data may be obtained in the form of plural prints, and this has led not only to the requirement of the space available for such copies to be installed, but also to the waste of expenses or maintenance of the apparatus or the waste of time.
As the low-speed recording such as facsimile or the like, there may be mentioned the discharge breakdown recording, the electrolytic recording, etc.
In the discharge breakdown recording, a layer of white pigment is provided on a black conductive layer or a thin layer of conductive material such as aluminum or the like is provided on a black layer, and discharging of a recording needle (hereinafter referred to as the stylus) is used to form apertures in the surface layer to expose the underlying black layer, thereby providing an image.
On the other hand, in the electrolytic recording system, paper is impregnated and wetted with electrolytic solution, and a current is supplied thereto from a stylus to thereby provide an image. The image so provided is formed of either a coloring substance resulting from the metal of the stylus having been ionized and reacted to the electrolyte or a cracked coloring product resulting from the electrolyte in the paper having been electrolyzed by the current from the stylus.
The discharge breakdown recording, however, is inconvenient in that the discharging heat from the stylus perforates the surface layer during the recording to create a very strong stimulant smell or to scatter the powdered material of the surface layer or to cause serious consumption of the stylus. Also, the black layer becomes exposed due to mechanical forces such as bending or pressure contact, so that the paper is liable to be stained. In addition, the surface layer is so thin as to readily permit occurrence of the discharge, and is not enough to completely cover the underlying black layer, and this causes the ground color of the recording paper to present gray instead of white, which leads to an unpleasant feeling of the paper. On the other hand, in the electrolytic recording which is of the wet type, the recording paper is so poor in preservability that the quality of image formed thereon tends to be deteriorated by blur. Further, after the recording, the paper tends to undergo waving or like deterioration due to drying. These are fatal disadvantages peculiar to the wet type recording.
Also, as disclosed in Japanese Patent Publications Nos. 22341/1963 and 29630/1969, there have been proposed the wet type electrifiable recording sheets in which electrically reducible metal compounds dispersed in an insulative resin material are reduced to free metals by passage of a current therethrough to thereby provide an image, but most of the relatively highly conductive metal compounds are colored while the less colored metal compounds are low in conductivity and therefore, some chemical treatment is required to permit passage of a current through the metal compounds. However, such treatment causes the metal compounds to be so much colored that the ground color density of the recording paper generally becomes higher. In addition, the low readiness of the metal compounds for passing the current therethrough would cause occurrence of discharge during the recording and the discharging heat would in turn produce an unpleasant smell or great consumption of the stylus. Further, Japanese Patent Publications Nos. 5476/1967 and 13239/1967 disclose the methods which use the technique of evaporation to form conductive skin films on white or transparent substances such as silica or the like, and thereafter disperse these into a matrix to permit passage of a current therethrough, but these methods also require considerable contrivances in the treating steps.
Thus, any of the conventional recording methods has lacked an effective dry type means for permitting passage of the current and raised various problems during the recording.
Further, where it is desired to obtain a plurality of prints from the image visualized by the above-described systems, such image has only served as a mere image original on the copying machine and this has led to waste as already described.